ALTHOUGH THE recession seems to have diminished attendance on Broadway, the impact of hard times is not so clear cut in Washington, where a few theaters have had extremely successful seasons and others have at Least held fast.

The big winner in the statistics sweepstakes was Arena Stage, which had an 8.6 percent increase in attendance, to 87.5 percent of capacity, for its eight-play series, and a season public relations director Richard Bryant described as "extraordinary." The most disappointing was the Eisenhower Theater series, which played at between 65 and 75 percent capacity, a weak turnout considering the generally adventurous season and well-known performers like Jean Stapleton, Zoe Caldwell, Irene Worth and Brian Bedford. So far the most successful of the six-play series, which will conclude with "Ghosts" starring Liv Ullman next month, is the current "The Dining Room."

Even the small theaters, always clinging precariously to life, had as many or more audience members this year as last. The Source Theatre, for example, had fewer performances in its 49-seat main theater at 1809 14th St. this season, but played at 74 percent capacity as opposed to 60.3 percent. The difference was attributable to one hit show--"Bent"--which played 12 sold-out weeks and drew much support from the gay community.

The Studio Theatre, which increased its seating capacity this year from 95 to 110 seats, continued to play at about 65 percent capacity. The Round House Theater in Silver Spring sold out three of the five shows in its season and played at 82.6 percent capacity overall.

Good ticket sales do not mean a theater is financially secure, because box office revenue covers only a portion of expenses even in the best of times. The New Playwrights' Theatre, for example, increased the number of performances as well as the number of people attending. It played to an average capacity of 78 percent this year as opposed to 69.8 percent last year, and box office revenues increased by $25,700. But the theater is still threatened by extinction for want of another $20,000.

Even Arena Stage, which extended the runs of three shows, will be about $90,000 in the hole when all the receipts are counted, according to current figuring. Ticket prices will rise next year to a top of $16.75, a $2.50 increase from this year.

The Folger Theatre had an uneven season, but rounded out with an overall 89.5 percent of capacity thanks largely to a hit production of "A Comedy of Errors." The theater also reports a dramatic 300 percent increase in requests for subscription tickets for next year, which management partly attributes to the addition of reserved seating. Ford's, on the other hand, played fewer weeks (29 this year; 39 last), and lost business, playing at 52 percent of capacity. Its one hit out of four productions was the evergreen "A Christmas Carol," which sold out all four weeks.

No reliable conclusions about community taste can be drawn about the choice of plays, either. Washington audiences appear to be willing to see any play as long as it is well done. Although "A Lesson From Aloes," the austere South African drama, did the least well of Arena Stage's eight plays despite critical acclaim, it was still successful and better received here than in other cities where productions were mounted this past season. "K-2," a grim drama with a spectacular set, is doing as well at the box office there as "Animal Crackers," a zany musical. At the suburban Roundhouse, Chekhov's "Three Sisters" did as well as the easy-to-digest "Deathtrap."

Big-name musicals and stars do not seem to have lost any appeal to theatergoers, who paid as much as $32.50 a ticket to see "Evita," and "The Pirates of Penzance" at the National and "Camelot" with Richard Harris at the Warner. "Sugar Babies," without well-known performers, is closing two weeks early at the Opera House, while Katharine Hepburn in a trivial play was a sellout at the same place. "Othello," starring James Earl Jones and Christopher Plummer, did as well overall as "Camelot" at the Warner, and the theater closed out its season of four shows with an overall average of 71 percent capacity, which is within the norm this year for road shows everywhere.

The Olney, a summer theater fixture for 30 years, raised its prices by 8 percent but did not lose any subscribers. Inflation will wipe out the increased revenue, however, and the theater will end up just about even.